Background Detection in Image Forming Apparatus via Periodic Charging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current image forming apparatuses face challenges in detecting background occurrences, which lead to unwanted toner consumption and image quality degradation due to the difficulty in identifying a low voltage range where no background is present, especially in color printing systems where noise from the intermediate transfer belt and sensor characteristics complicate initial state background detection.
Innovation Solution
The apparatus employs a method to change the charging power supply periodically, generating a potential difference at predetermined periods to identify background presence through image density changes, and adjusts light emission amounts for precise detection, allowing for sequential monitoring of multiple photosensitive drums to reduce background detection time and improve sensing resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional background detection methods are used in color printing systems, then initial state background detection can be performed, but noise from the intermediate transfer belt and sensor characteristics complicate detection leading to unwanted toner consumption and image quality degradation
Solution Approach 1:
The patent applies periodic action by periodically changing the charging power supply to the photosensitive drum at predetermined periods. This creates periodic variations in image density that can be detected and analyzed. By using periodic charging power changes, the system can distinguish between actual background occurrences and random noise from the intermediate transfer belt or sensor characteristics, thereby improving background detection precision while reducing false positives that lead to unwanted toner consumption.
Solution Approach 2:
The patent employs parameter changes by modifying the charging power supply parameters (voltage, current, or power levels) periodically applied to the photosensitive drum. By changing these electrical parameters and observing the corresponding changes in image density, the system can identify background occurrences more accurately. This approach transforms the detection method from static threshold-based detection to dynamic parameter-based detection, reducing the impact of noise from the intermediate transfer belt and sensor characteristics.
2Reliability
If charging power is increased to prevent background, then image quality is maintained, but toner consumption increases and energy efficiency decreases
Solution Approach 1:
The patent implements feedback by continuously monitoring image density changes in response to periodic charging power supply changes. The system analyzes the detected image density variations and uses this information to determine whether background occurrences are present. Based on this feedback, the controller adjusts the charging power supply to maintain image quality while avoiding excessive toner consumption. This closed-loop control ensures that charging power is optimized rather than simply increased, preventing both background defects and unnecessary toner waste.
3Measurement precision
If background detection is performed continuously, then detection accuracy is improved, but detection time increases and productivity decreases
Solution Approach 1:
The patent uses periodic action by performing background detection at predetermined intervals rather than continuously. The charging power supply is changed periodically, and image density is measured at these specific intervals. This periodic detection approach maintains sufficient detection accuracy for identifying background occurrences while significantly reducing the time spent on detection compared to continuous monitoring, thereby preserving printing productivity and speed.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively identifies background occurrences and determines the charging voltage margin, preventing image quality degradation and reducing toner consumption by accurately determining the voltage range where no background exists, enabling efficient print operations.
Implementation Method 1
a charging member charging a photosensitive drum
Implementation Method 2
an image density of an image formed on an image forming medium is detected
Data Source
AI summary
An image forming apparatus includes a print engine including a photosensitive drum forming an image on an image forming medium, a charging member charging the photosensitive drum, a power supply to provide a charging power supply having a reference charging voltage to the charging member, a sensor to detect an image density of an image formed on the image forming medium, and a processor to control the power supply to change a magnitude of voltage of the charging power supply within a predetermined voltage range at predetermined periods, and to identify an occurrence of a background with respect to the photosensitive drum based on an image density detected by the sensor while the charging power supply is changed.